Acoustic systems for electronic devices

ABSTRACT

A portable electronic device may have acoustic ports such as microphone and speaker ports. Acoustic devices such as microphones and speakers may be associated with the acoustic ports. An acoustic port may have an opening between an interior and exterior of the portable electronic device. The opening may be covered by a metal mesh. An acoustic fabric may be interposed between the metal mesh and the opening. The opening may be formed from a hole in a glass member having outer and inner chamfers. A microphone boot may be provided that forms front and rear radial seals with a housing of the device and a microphone unit respectively. The microphone boot may also form multiple face seals with the microphone unit. A speaker for the speaker port may be enclosed in a sealed speaker enclosure. The speaker enclosure may have a pressure-equalizing vent slit covered with an acoustic mesh.

This application claims the benefit of provisional patent applicationNos. 61/044,347, filed Apr. 11, 2008, 61/041,522, filed Apr. 1, 2008,and 61/041,532, filed Apr. 1, 2008, which are hereby incorporated byreference herein in their entireties.

BACKGROUND

This invention relates generally to electronic devices, and moreparticularly, to acoustic systems for portable electronic devices suchas handheld electronic devices.

Handheld electronic devices and other portable electronic devices arebecoming increasingly popular. Examples of handheld devices includehandheld computers, cellular telephones, media players, and hybriddevices that include the functionality of multiple devices of this type.Popular portable electronic devices that are somewhat larger thantraditional handheld electronic devices include laptop computers andtablet computers.

Portable electronic devices such as handheld electronic devices mayinclude acoustic components such as microphones and speakers. Forexample, cellular telephones have microphones and receiver speakers.Many cellular telephones also have speakerphone speakers.

It can be difficult to satisfactorily integrate acoustic components intocompact electrical devices. If care is not taken, acoustic performancewill suffer and devices will not be sufficiently protected fromenvironmental effects.

It would therefore be desirable to be able to provide electronic devicessuch as portable electronic devices with improved acoustic features.

SUMMARY

A portable electronic device such as a handheld electronic device isprovided. The device may have acoustic ports. The acoustic ports mayinclude a microphone port and one or more speaker ports. The speakerports may be used as speakerphone ports or as ear speakers for areceiver when the device is used as a telephone.

The acoustic ports may be formed from openings in the housing for theportable electronic device. The openings may be covered with one or morelayers of mesh. For example, the openings may be covered with a metalmesh. A layer of acoustic fabric may be interposed between the metalmesh and each opening. The metal mesh may have larger holes than theacoustic mesh. This may make the metal mesh more attractive inappearance than the acoustic mesh. Because the metal mesh is formed frommetal wires rather than nonmetallic threads, the metal mesh may be moreresistant to damage than nonmetallic fabrics. The finer holes availablein the acoustic mesh may help to prevent intrusion of fine particlesthat pass through the metal mesh.

Layer of adhesive may be used to connect the metal and acoustic meshesto the device. If desired, an acoustic port such as a receiver speakerport may be formed from an opening in a cover glass that is otherwiseused to cover a display unit. The opening in the cover glass may haveouter and inner chamfers. The lower surface of the cover glass may becovered with ink. A layer of adhesive may be used to connect a speakerto the cover glass. The layer of adhesive may create an air gap betweenthe metal mesh and the ink, so that the ink is not scratched by metalstrands in the mesh.

A microphone port may have a microphone unit and an elastomericmicrophone boot. The microphone boot may have an opening that permitssound to enter the microphone unit from outside of the portableelectronic device. A front portion of the microphone boot may formenvironmental seals with the housing of the portable electronic device.Raised ribs or other engagement features may be used to form a radialseal between the boot and the housing. A rear portion of the microphoneboot may form environmental seals with the microphone unit. A frontsurface of the microphone unit may form a front face seal with themicrophone boot. A rear surface of the microphone unit may form a rearface seal with the microphone boot. A surface on the microphone unitthat is located between the front and rear surfaces may form a radialseal with the microphone boot. Metal mesh and acoustic fabric may beused to cover the opening.

Further features of the invention, its nature and various advantageswill be more apparent from the accompanying drawings and the followingdetailed description of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an illustrative portable electronicdevice in accordance with an embodiment of the present invention.

FIG. 2 is a schematic diagram of an illustrative portable electronicdevice in accordance with an embodiment of the present invention.

FIG. 3 is an exploded perspective view of an illustrative portableelectronic device in accordance with an embodiment of the presentinvention.

FIG. 4 is an exploded perspective view of a multilayer mesh arrangementthat may be provided in an acoustic port such as a microphone or speakerport in accordance with an embodiment of the present invention.

FIG. 5 is a cross-sectional side view showing illustrative layers ofmaterial that may be included in an acoustic port in accordance with anembodiment of the present invention.

FIG. 6 is a cross-sectional side view of an illustrative acoustic portwith a chamfered opening in accordance with an embodiment of the presentinvention.

FIG. 7 is a perspective view of an illustrative speaker box with a venthole in accordance with an embodiment of the present invention.

FIG. 8 is a cross-sectional side view of an illustrative vent in aspeaker enclosure in accordance with an embodiment of the presentinvention.

FIG. 9 is a cross-sectional side view of an illustrative speakerenclosure with a multihole vent structure in accordance with anembodiment of the present invention.

FIG. 10 is a cross-sectional side view of an illustrative speakerenclosure with a separate vent hole structure that has been attached toone side of the speaker enclosure in accordance with an embodiment ofthe present invention.

FIG. 11 is a cross-sectional side view of an illustrative speakerenclosure with a vent hole structure to which a speaker enclosure hasbeen attached using an overmolding process in accordance with anembodiment of the present invention.

FIG. 12 is an exploded perspective view of an illustrative speakerenclosure and associated components in accordance with an embodiment ofthe present invention.

FIG. 13 is a perspective view of an illustrative speaker enclosure andassociated components in accordance with an embodiment of the presentinvention.

FIG. 14 is a cross-sectional side view of a microphone boot structureshowing a microphone-boot-to-housing seal in accordance with anembodiment of the present invention.

FIG. 15 is a cross-sectional side view of a microphone boot structureshowing a microphone-boot-to-microphone seal in accordance with anembodiment of the present invention.

FIG. 16 is a cross-sectional view of a sealing arrangement withsemicircular recesses that may be used in forming a seal for an acousticcomponent in accordance with an embodiment of the present invention.

FIG. 17 is an end view of an illustrative acoustic component having anacoustic opening in accordance with an embodiment of the presentinvention.

FIG. 18 is a cross-sectional view of a sealing arrangement withsemicircular protrusions that may be used in forming a seal for anacoustic component in accordance with an embodiment of the presentinvention.

FIG. 19 is a cross-sectional view of a sealing arrangement withtriangular recesses that may be used in forming a seal for an acousticcomponent in accordance with an embodiment of the present invention.

FIG. 20 is a cross-sectional view of a sealing arrangement with squarerecesses that may be used in forming a seal for an acoustic component inaccordance with an embodiment of the present invention.

DETAILED DESCRIPTION

The present invention relates to acoustic systems for electronicdevices.

The electronic devices may be portable electronic devices such as laptopcomputers or small portable computers of the type that are sometimesreferred to as ultraportables. Portable electronic devices may also besomewhat smaller devices. Examples of smaller portable electronicdevices include wrist-watch devices, pendant devices, headphone andearpiece devices, and other wearable and miniature devices. With onesuitable arrangement, the portable electronic devices may be wirelesselectronic devices.

The wireless electronic devices may be, for example, handheld wirelessdevices such as cellular telephones, media players with wirelesscommunications capabilities, handheld computers (also sometimes calledpersonal digital assistants), remote controllers, global positioningsystem (GPS) devices, and handheld gaming devices. The wirelesselectronic devices may also be hybrid devices that combine thefunctionality of multiple conventional devices. Examples of hybridportable electronic devices include a cellular telephone that includesmedia player functionality, a gaming device that includes a wirelesscommunications capability, a cellular telephone that includes game andemail functions, and a portable device that receives email, supportsmobile telephone calls, has music player functionality and supports webbrowsing. These are merely illustrative examples.

An illustrative portable electronic device in accordance with anembodiment of the present invention is shown in FIG. 1. Device 10 ofFIG. 1 may be, for example, a handheld electronic device that supports2G and/or 3G cellular telephone and data functions, global positioningsystem capabilities, and local wireless communications capabilities(e.g., IEEE 802.11 and Bluetooth®) and that supports handheld computingdevice functions such as internet browsing, email and calendarfunctions, games, music player functionality, etc.

Device 10 may have housing 12. Antennas for handling wirelesscommunications may be housed within housing 12 (as an example).

Housing 12, which is sometimes referred to as a case, may be formed ofany suitable materials including, plastic, glass, ceramics, metal, orother suitable materials, or a combination of these materials. In somesituations, housing 12 or portions of housing 12 may be formed from adielectric or other low-conductivity material, so that the operation ofconductive antenna elements that are located in close proximity tohousing 12 is not disrupted. Housing 12 or portions of housing 12 mayalso be formed from conductive materials such as metal. An advantage offorming housing 12 from a dielectric material such as plastic is thatthis may help to reduce the overall weight of device 10 and may avoidpotential interference with wireless operations.

In scenarios in which housing 12 is formed from metal elements, one ormore of the metal elements may be used as part of the antennas in device10. For example, metal portions of housing 12 may be shorted to aninternal ground plane in device 10 to create a larger ground planeelement for that device 10.

Housing 12 may have a bezel 14. The bezel 14 may be formed from aconductive material or other suitable material. Bezel 14 may serve tohold a display or other device with a planar surface in place on device10 and may serve to form an esthetically pleasing trim around the edgeof device 10. As shown in FIG. 1, for example, bezel 14 may be used tosurround the top of display 16. Bezel 14 and/or other metal elementsassociated with device 10 may be used as part of the antennas in device10. For example, bezel 14 may be shorted to printed circuit boardconductors or other internal ground plane structures in device 10 toextend the ground plane element for device 10.

Display 16 may be a liquid crystal display (LCD), an organic lightemitting diode (OLED) display, or any other suitable display. Theoutermost surface of display 16 may be formed from one or more plasticor glass layers. If desired, touch screen functionality may beintegrated into display 16 or may be provided using a separate touch paddevice. An advantage of integrating a touch screen into display 16 tomake display 16 touch sensitive is that this type of arrangement cansave space and reduce visual clutter.

Display screen 16 (e.g., a touch screen) is merely one example of aninput-output device that may be used with electronic device 10. Ifdesired, electronic device 10 may have other input-output devices. Forexample, electronic device 10 may have user input control devices suchas button 19, and input-output components such as port 20 and one ormore input-output jacks (e.g., for audio and/or video). Button 19 maybe, for example, a menu button. Port 20 may contain a 30-pin dataconnector (as an example). Openings 22 and 24 may, if desired, formspeaker and microphone ports. Speaker port 22 may be used when operatingdevice 10 in speakerphone mode. Opening 23 may also form a speaker port.For example, speaker port 23 may serve as a telephone receiver that isplaced adjacent to a user's ear during operation. In the example of FIG.1, display screen 16 is shown as being mounted on the front face ofhandheld electronic device 10, but display screen 16 may, if desired, bemounted on the rear face of handheld electronic device 10, on a side ofdevice 10, on a flip-up portion of device 10 that is attached to a mainbody portion of device 10 by a hinge (for example), or using any othersuitable mounting arrangement.

A user of electronic device 10 may supply input commands using userinput interface devices such as button 19 and touch screen 16. Suitableuser input interface devices for electronic device 10 include buttons(e.g., alphanumeric keys, power on-off, power-on, power-off, and otherspecialized buttons, etc.), a touch pad, pointing stick, or other cursorcontrol device, a microphone for supplying voice commands, or any othersuitable interface for controlling device 10. Although shown as beingformed on the top face of electronic device 10 in the example of FIG. 1,buttons such as button 19 and other user input interface devices maygenerally be formed on any suitable portion of electronic device 10. Forexample, a button such as button 19 or other user interface control maybe formed on the side of electronic device 10. Buttons and other userinterface controls can also be located on the top face, rear face, orother portion of device 10. If desired, device 10 can be controlledremotely (e.g., using an infrared remote control, a radio-frequencyremote control such as a Bluetooth® remote control, etc.).

Electronic device 10 may have ports such as port 20. Port 20, which maysometimes be referred to as a dock connector, 30-pin data portconnector, input-output port, or bus connector, may be used as aninput-output port (e.g., when connecting device 10 to a mating dockconnected to a computer or other electronic device). Port 20 may containpins for receiving data and power signals. Device 10 may also have audioand video jacks that allow device 10 to interface with externalcomponents. Ports may include power pins to recharge a battery withindevice 10 or to operate device 10 from a direct current (DC) powersupply, data pins to exchange data with external components such as apersonal computer or peripheral, audio-visual jacks to drive headphones,a monitor, or other external audio-video equipment, a subscriberidentity module (SIM) card port to authorize cellular telephone service,a memory card slot, etc. The functions of some or all of these devicesand the internal circuitry of electronic device 10 can be controlledusing input interface devices such as touch screen display 16. Touchscreen display 16 may be, for example, a capacitive multitouch touchscreen.

Components such as display 16 and other user input interface devices maycover most of the available surface area on the front face of device 10(as shown in the example of FIG. 1) or may occupy only a small portionof the front face of device 10. Because electronic components such asdisplay 16 often contain large amounts of metal (e.g., asradio-frequency shielding), the location of these components relative tothe antenna elements in device 10 should generally be taken intoconsideration. Suitably chosen locations for the antenna elements andelectronic components of the device will allow the antennas ofelectronic device 10 to function properly without being disrupted by theelectronic components.

Examples of locations in which antenna structures may be located indevice 10 include region 18 and region 21. These are merely illustrativeexamples. Any suitable portion of device 10 may be used to house antennastructures for device 10 if desired.

A schematic diagram of an embodiment of an illustrative portableelectronic device such as a handheld electronic device is shown in FIG.2. Portable device 10 may be a mobile telephone, a mobile telephone withmedia player capabilities, a handheld computer, a remote control, a gameplayer, a global positioning system (GPS) device, a laptop computer, atablet computer, an ultraportable computer, a hybrid device thatincludes the functionality of some or all of these devices, or any othersuitable portable electronic device.

As shown in FIG. 2, device 10 may include storage 34. Storage 34 mayinclude one or more different types of storage such as hard disk drivestorage, nonvolatile memory (e.g., flash memory or otherelectrically-programmable-read-only memory), volatile memory (e.g.,battery-based static or dynamic random-access-memory), etc.

Processing circuitry 36 may be used to control the operation of device10. Processing circuitry 36 may be based on a processor such as amicroprocessor and other suitable integrated circuits. With one suitablearrangement, processing circuitry 36 and storage 34 are used to runsoftware on device 10, such as internet browsing applications,voice-over-internet-protocol (VOIP) telephone call applications, emailapplications, media playback applications, operating system functions,etc. Processing circuitry 36 and storage 34 may be used in implementingsuitable communications protocols. Communications protocols that may beimplemented using processing circuitry 36 and storage 34 includeinternet protocols, wireless local area network protocols (e.g., IEEE802.11 protocols—sometimes referred to as Wi-Fi®), protocols for othershort-range wireless communications links such as the Bluetooth®protocol, protocols for handling 3 G communications services (e.g.,using wide band code division multiple access techniques), 2 G cellulartelephone communications protocols, etc.

To minimize power consumption, processing circuitry 36 may include powermanagement circuitry to implement power management functions. Duringoperation, the power management circuitry or other processing circuitry36 may be used to adjust power supply voltages that are provided toportions of the circuitry on device 10. For example, higherdirect-current (DC) power supply voltages may be supplied to activecircuits and lower DC power supply voltages may be supplied to circuitsthat are less active or that are inactive.

Input-output devices 38 may be used to allow data to be supplied todevice 10 and to allow data to be provided from device 10 to externaldevices. Display screen 16, button 19, microphone port 24, speaker port22, and dock connector port 20 are examples of input-output devices 38.

Input-output devices 38 can include user input-output devices 40 such asbuttons, touch screens, joysticks, click wheels, scrolling wheels, touchpads, key pads, keyboards, microphones, cameras, etc. A user can controlthe operation of device 10 by supplying commands through user inputdevices 40. Display and audio devices 42 may include liquid-crystaldisplay (LCD) screens or other screens, light-emitting diodes (LEDs),and other components that present visual information and status data.Display and audio devices 42 may also include audio equipment such asspeakers and other devices for creating sound. Display and audio devices42 may contain audio-video interface equipment such as jacks and otherconnectors for external headphones and monitors.

Wireless communications devices 44 may include communications circuitrysuch as radio-frequency (RF) transceiver circuitry formed from one ormore integrated circuits, power amplifier circuitry, passive RFcomponents, antennas, and other circuitry for handling RF wirelesssignals. Wireless signals can also be sent using light (e.g., usinginfrared communications).

Device 10 can communicate with external devices such as accessories 46,computing equipment 48, and wireless network 49 as shown by paths 50 and51. Paths 50 may include wired and wireless paths. Path 51 may be awireless path. Accessories 46 may include headphones (e.g., a wirelesscellular headset or audio headphones) and audio-video equipment (e.g.,wireless speakers, a game controller, or other equipment that receivesand plays audio and video content), a peripheral such as a wirelessprinter or camera, etc.

Computing equipment 48 may be any suitable computer. With one suitablearrangement, computing equipment 48 is a computer that has an associatedwireless access point (router) or an internal or external wireless cardthat establishes a wireless connection with device 10. The computer maybe a server (e.g., an internet server), a local area network computerwith or without internet access, a user's own personal computer, a peerdevice (e.g., another portable electronic device 10), or any othersuitable computing equipment.

Wireless network 49 may include any suitable network equipment, such ascellular telephone base stations, cellular towers, wireless datanetworks, computers associated with wireless networks, etc. For example,wireless network 49 may include network management equipment thatmonitors the wireless signal strength of the wireless handsets (cellulartelephones, handheld computing devices, etc.) that are in communicationwith network 49.

The antenna structures and wireless communications devices of device 10may support communications over any suitable wireless communicationsbands. For example, wireless communications devices 44 may be used tocover communications frequency bands such as cellular telephone voiceand data bands at 850 MHz, 900 MHz, 1800 MHz, 1900 MHz, and 2100 MHz (asexamples). Devices 44 may also be used to handle the Wi-Fi® (IEEE802.11) bands at 2.4 GHz and 5.0 GHz (also sometimes referred to aswireless local area network or WLAN bands), the Bluetooth® band at 2.4GHz, and the global positioning system (GPS) band at 1575 MHz.

Device 10 can cover these communications bands and other suitablecommunications bands with proper configuration of the antenna structuresin wireless communications circuitry 44. Any suitable antenna structuresmay be used in device 10. For example, device 10 may have one antenna ormay have multiple antennas. The antennas in device 10 may each be usedto cover a single communications band or each antenna may cover multiplecommunications bands. If desired, one or more antennas may cover asingle band while one or more additional antennas are each used to covermultiple bands. As an example, a pentaband cellular telephone antennamay be provided at one end of device 10 (e.g., in region 18) to handle 2G and 3 G voice and data signals and a dual band antenna may be providedat another end of device 10 (e.g., in region 21) to handle GPS and 2.4GHz signals. The pentaband antenna may be used to cover wireless bandsat 850 MHz, 900 MHz, 1800 MHz, 1900 MHz, and 2100 MHz (as an example).The dual band antenna 63 may be used to handle 1575 MHz signals for GPSoperations and 2.4 GHz signals (for Bluetooth® and IEEE 802.11operations). These are merely illustrative arrangements. Any suitableantenna structures may be used in device 10 if desired.

To facilitate manufacturing operations, device 10 may be formed from twointermediate assemblies, representing upper and lower portions of device10. The upper or top portion of device 10 may sometimes be referred toas a tilt assembly. The lower or bottom portion of device 10 maysometimes be referred to as a housing assembly.

The tilt and housing assemblies may each be formed from a number ofsmaller components. For example, the tilt assembly may be formed fromcomponents such as display 16 and an associated touch sensor. Thehousing assembly may include a plastic housing portion 12 and printedcircuit boards. Integrated circuits and other components may be mountedon the printed circuit boards. During manufacturing, one end of the tiltassembly may be inserted into the housing assembly. The tilt assemblymay then be rotated (“tilted”) into place so that the upper surface ofthe tilt assembly lies flush with the upper edges of the housingassembly.

An exploded perspective view showing illustrative components of device10 is shown in FIG. 3.

Tilt assembly 60 (shown in its unassembled state in FIG. 3) may includecomponents such as cover 62, touch sensitive sensor 64, display unit 66,and frame 68. Cover 62 may be formed of glass or other suitabletransparent materials (e.g., plastic, combinations of one or moreglasses and one or more plastics, etc.). Display unit 66 may be, forexample, a color liquid crystal display. Frame 68 may be formed from oneor more pieces. With one suitable arrangement, frame 68 may includemetal pieces to which plastic parts are connected using an overmoldingprocess. If desired, frame 68 may be formed entirely from plastic orentirely from metal.

Housing assembly 70 (shown in its unassembled state in FIG. 3) mayinclude housing 12. Housing 12 may be formed of plastic and/or othermaterials such as metal (metal alloys). For example, housing 12 may beformed of plastic to which metal members are mounted using fasteners, aplastic overmolding process, or other suitable mounting arrangement.

As shown in FIG. 3, handheld electronic device 10 may have a bezel suchas bezel 14. Bezel 14 may be formed of plastic or other dielectricmaterials or may be formed from metal or other conductive materials. Anadvantage of a metal (metal alloy) bezel is that materials such as metalmay provide bezel 14 with an attractive appearance and may be durable.If desired, bezel 14 may be formed from shiny plastic or plastic coatedwith shiny materials such as metal films.

Bezel 14 may be mounted to housing 12. Following final assembly, bezel14 may surround the display of device 10 and may, if desired, helpsecure the display onto device 10. Bezel 14 may also serve as a cosmetictrim member that provides an attractive finished appearance to device10.

Housing assembly 70 may include battery 74. Battery 74 may be, forexample, a lithium polymer battery having a capacity of about 1300mA-hours. Battery 74 may have spring contacts that allow battery 74 tobe serviced.

Housing assembly 70 may also include one or more printed circuit boardssuch as printed circuit board 72. Housing assembly 70 may also includecomponents such as microphone 76 for microphone port 24, speaker 78 forspeaker port 22, and dock connector 20, integrated circuits, a camera,ear speaker for port 23, audio jack, buttons, SIM card slot, etc.

Acoustic ports such as microphone port 24 and speaker ports 22 and 23represent an interface between the exterior of device 10 and theinterior of device 10. Acoustic components such as microphone andspeaker components are housed in the interior of device 10. Microphonesmust receive sound from the exterior of device 10. Speakers musttransmit sound to the exterior of device3 10. At the same time, unwantedincursions of foreign matter into the interior of device 10 should beprevented or at least minimized.

To maximize acoustic performance while protecting the interior of device10 from foreign matter incursions, one or more of the acoustic ports indevice 10 may be provided with structures that permit sound to passwhile blocking unwanted matter. These structures may help to ensure thatacoustic performance is not degraded while providing an attractiveappearance to the exterior of device 10.

Components in an illustrative acoustic port arrangement are shown in theexploded perspective view of FIG. 4. As shown in FIG. 4, port 100 may beformed from one or more holes such as hole 102 in a housing wall orother device structure 80. Port 100 may be, for example, a microphoneport or a speaker port. There may be any suitable number of holes 102associated with port 100. In the example of FIG. 4, a single hole 102 isassociated with port 100. Structure 80 may be a housing wall (e.g., aportion of housing 12), a housing wall and other associated devicestructures (e.g., a housing wall and structures adjacent to the interiorof the housing wall), a cover glass such as cover glass 64 (FIG. 3), orany other suitable structure that separates the interior of device 10from the exterior of device 10. Openings such as opening 102 aregenerally exposed to air, when device 10 is in normal use.

Acoustic structures are mounted behind opening 102. In one suitablearrangement, which is described herein as an example, multiple layers ofmesh are mounted behind opening 102. These layers lie between opening102 and acoustic component 90. Acoustic component 90 may be a microphoneor a speaker. Region 92 of component 90 may include an opening and anassociated speaker or microphone diaphragm. Structures such as these mayalso be recessed further within acoustic component 90 if desired.

The acoustic structures that are mounted between opening 102 and opening92 may include one or more layers of mesh-type structures that helpprevent intrusion of foreign matter. In the illustrative configurationof FIG. 4, the outermost layer of acoustic material is mesh 82. Mesh 82,which may sometimes be referred to as a grill, may be formed of strandsof metal or other suitable material (e.g., plastic). An advantage ofusing metal to form wires in mesh 82 is that metal tends to be durableand resistant to damage from environmental exposure. Metal also may beused to prevent an attractive appearance to users who are viewing port100 from the exterior of device 10. Metal mesh 82 may be robust enoughto withstand impact when a user attempts to clean opening 102 of port100.

Any suitable mesh size may be used for mesh 82. For example, if mesh 82is being used to cover a hole 102 that has lateral dimensions of about 2mm (as an example), mesh 82 may be woven tightly enough to ensure thatthere are at least 10 or more strands of metal wire across the opening(i.e., the strand density may be a minimum of about 5 wires/mm). Largerstrand densities (e.g., 20 wires/mm) may also be used, although careshould be taken to maintain the strand density low enough to permitsound to readily pass through metal mesh 82 during operation of acousticdevice 90. With one particularly suitable arrangement, mesh 82 is a #100mesh having about a wire diameter of about 0.11 mm and a mesh hole sizeof about 0.14 mm (as an example).

If desired, the appearance of mesh 82 may be tailored by coating wires94 or by using wires 94 with a particular appearance. Wires 94 may, forexample, be formed from a shiny substance such as brass or stainlesssteel or may be coated with a color (e.g., colored paint or coloredplastic jacket materials). Combinations of colored and shiny wires mayalso be used.

One or more layers of acoustic mesh may be included in the acousticstructures between opening 102 and region 92. In the example of FIG. 4,a single layer 86 of acoustic mesh is shown. Acoustic mesh 86, which maysometimes be referred to as speaker fabric, may be used to adjust theacoustic impedance properties of metal mesh 82 and may help to blockfine particles such as those that might not otherwise be blocked bymetal mesh 82. Illustrative acoustic mesh materials that may be used foracoustic mesh layer 86 include the woven polyester and wovenpolyester/PVC-on-polyester fabrics referred to as AcousTex® fabricavailable from AcousTex Fabrics of Burlington, Mass. In general,acoustic mesh material may be formed from any suitable fabric materialthat exhibits satisfactory acoustic performance (e.g., soundtransparency of 90% or more, etc.). Such acoustic fabrics generally havemesh openings that are smaller than the openings of the cosmetic metalmesh 82. Such acoustic fabrics are also generally formed fromnonmetallic (e.g., nonconductive) materials.

When both metal mesh 82 and acoustic mesh 86 are used together in port100, performance may be enhanced. For example, acoustic mesh 86 may helpimprove the acoustics of port 100. At the same time, metal mesh 82 mayimprove the appearance and robustness of port 100 beyond what wouldotherwise be achieved using only acoustic mesh 86.

Any suitable fastening arrangement may be used to secure the layers ofmesh for port 100. For example, layers of adhesive film (double-sidedtape) may be interposed between the mesh layers. The adhesive film maybe based on a metal film or plastic foil or any other suitable backingmaterial coated with a pressure sensitive adhesive. These layers may beprovided in the form of strips surrounding the periphery of portopenings such as opening 102, may be provided in the form of rings thatsurround each port opening, or may be provided in any other suitableshape. In the example of FIG. 4, adhesive film layers are provided inthe form of ring-shaped layers that surround opening 102. Adhesive filmlayer 104 may help secure metal mesh 82 to the interior surface ofdevice structure 80. Adhesive ring 84 may be used to adhere acousticmesh 86 to metal mesh 82. Adhesive ring layer 88 may be used to attachacoustic mesh layer 86 to acoustic device 90. The openings in theserings (e.g., openings 106, 96, and 98) may be aligned with opening 102and region 92. If desired, adhesive may be used to secure component 90to structure 80 (e.g., in addition to or instead of using adhesive 104).

If desired, other fastening mechanisms may be used to secure the layersof mesh for port 100. For example, mesh layers may be held in place byscrews or other fasteners, by liquid adhesive (e.g., adhesive notassociated with layers of film), by confining the layers betweenstructure 80 and component 90 using pressure, or using any othersuitable arrangement. The use of adhesive film layers is merelyillustrative.

An advantage of using layers of adhesive film is that such layers mayhelp to prevent damage to device structures from contact with wires 94of mesh 82. For example, in configurations in which structure 80 forms aglass cover (e.g., cover glass 62 of FIG. 3), adhesive film such asadhesive film 104 of FIG. 4 may help prevent wires 94 from scratchingthe underside of the glass.

A cross-sectional view of an illustrative port 100 that has layers ofmesh is shown in FIG. 5. As shown in FIG. 5, metal mesh layer 82 may belocated adjacent to opening 102 in structure 80. Opening 102 may beassociated with microphone port 24 (FIG. 1), speakerphone speaker port22 (FIG. 1), receiver speaker port 23 (FIG. 1), or any other suitableacoustic port. Acoustic mesh layers such as layer 86 of FIG. 5 may beinterposed between metal mesh 82 and a microphone or speaker (acousticdevice 90).

If desired, an opening may be provided in a structure such as coverglass 62 (FIG. 2). This type of opening may be used, for example, toform a receiver port such as receiver port 23. As shown in FIG. 6,receiver port 23 may be formed from an opening 110 in cover glass 62that is aligned with acoustic structure 92 of acoustic device 90.Acoustic structure 92 may be, for example, a microphone diaphragm or aspeaker cone. Structures 114 may include a durable protective outer meshsuch as wire mesh 82 of FIG. 4 and a less durable and more finely woveninner mesh such as mesh 86 of FIG. 4. Because the holes of the innermesh are smaller than the holes of the outer mesh, the inner mesh helpsto trap particles that might otherwise pass through the holes of theouter mesh. The inner mesh may also be chosen for its acoustic impedanceproperties (e.g., to tune the acoustic impedance properties of theacoustic port).

As shown in FIG. 6, opening 100 in glass 62 may have associated chamferssuch as outer surface chamfers 108 and inner surface chamfers 112.Chamfers 108 may be used to guide sound in and out of port 23. Chamfers112 may also be used to guide sound into and out of port 23 and mayimprove the acoustics of port 23. Moreover, inner chamfers 112 may helpto lower stress in structure 62, thereby reducing the likelihood ofchips in structure 62 in the vicinity of opening 110.

Adhesive layers such as double-sided adhesive film layer 116 may be usedto help prevent metal mesh 82 from damaging structure 62. For example,structure 62 may be a clear glass cover that is coated on its undersidewith a somewhat fragile layer of black ink 118 or other coating. Toprevent the wires of mesh 82 (FIG. 4) in structure 114 from scratchingink 118, adhesive film layer 116, which may be interposed betweenacoustic component 90 and the lower surface of structure 62 may be usedto create a vertical offset between ink 118 and structure 114. Ifdesired, adhesive film (e.g., adhesive film 104 of FIG. 4) may beinterposed between metal mesh 82 and ink 118 in addition to or insteadof relying on the space created by the thickness of layer 116 to protectink 118.

Device 10 may include a fully sealed speaker box. Fully enclosedspeakers may have improved acoustic performance relative to speakersthat are not enclosed. However, speakers that are mounted within sealedspeaker enclosures may be susceptible to damage. In particular, uponexposure to air pressure changes such as the pressure changes associatedwith airplane travel, the diaphragm of a speaker that is mounted in acompletely sealed speaker box may be damaged from excessive internal airpressure. In accordance with an embodiment of the present invention,damage of this type may be avoided by forming a thin slit or other airvent opening in the speaker box. The air vent may allow air to escapefrom the speaker box so that air pressures on either side of the speakerdiagram are equalized and damage from overpressuring one side of thespeaker relative to the other is avoided.

An illustrative speaker enclosure 118 that may be used in device 10 isshown in FIG. 7. Enclosure 118 may be formed from plastic or othersuitable materials. For example, enclosure 118 may be formed from anupper plastic half 122 and a lower plastic half 124 which are joinedalong seam 126 during manufacturing.

The interior of enclosure 118 may be hollow. Microphone 76 and speaker78, which are shown in FIG. 3, may be mounted to enclosure 118. Forexample, microphone 76 may be mounted to an exterior portion ofenclosure 118 in the vicinity of microphone port 20. Speaker 78 may bemounted in the hollow interior of enclosure 118 under region 120 in thevicinity of speaker port 22. Speaker 78 may have electrical terminalsthat are connected to audio circuitry in device 10. Speaker 78 may alsohave an actuator and a diaphragm that is driven by the actuator toproduce sound. The diaphragm may be formed from paper, plastic film, orany other suitable material or combinations of such materials. Whenmounted within enclosure 118, one side of the speaker diaphragm may beexposed to the exterior of enclosure 118 through the opening of speakerport 22 and the opposing side of the speaker diaphragm may be exposed tothe sealed interior of enclosure 118.

The substantially sealed nature of enclosure 118 forms a “closed-box”speaker architecture. In this type of architecture, the enclosed airserves as a spring that helps to drive the speaker accurately duringuse. The use of sealed enclosure 118 therefore helps to improve acousticperformance for speaker 76. However, the sealed nature of enclosure 118poses a challenge as device 10 is placed in environments of varyingpressure. If a sealed speaker box is maintained at sea level for anextended period of time, the pressure inside the box will equilibrate toatmospheric pressure at sea level. If the sealed speaker box is thenrapidly taken to a lower pressure environment (e.g., in an airplane),the diagram of the speaker may be damaged by the high internal pressureof the box relative to the lower environmental pressure outside of thebox.

Enclosure 118 of FIG. 7 avoids this potentially damaging situation byuse of a vent such as vent slit 128. Vent slit 128 may be provided inthe form of a relatively long and narrow opening between the interiorand exterior of enclosure 118. When atmospheric pressure is reducedoutside of enclosure 118, air can escape through vent slit 128. Thisequalizes the pressure on both sides of the speaker diaphragm andprevents damage. At the same time, vent slit 128 is preferably not toolarge, so that acoustically enclosure 118 continues to operate as aclosed speaker box.

Vent 128 may be formed in any suitable shape. For example, vent 128 maybe formed from a circular opening, an oval opening, a polygonal opening,multiple holes, etc. An advantage of using a slit-shaped (substantiallyrectangular) opening is that this allows vent 128 to be formed bycreating mating recesses in enclosure housing portions 122 and 124.These recesses may be formed as part of a plastic molding process usedto fabricate speaker box housing portions 122 and 124, thereby avoidingthe necessity for machining vent 128.

Vent 128 may be covered with an acoustic mesh 134. Acoustic mesh 124 mayhelp to raise the acoustic impedance of vent 128, so that speakerenclosure 118 acts as a completely closed speaker box, while permittingair to flow in and out of the interior of enclosure 118 to accommodateenvironmental pressure changes. Mesh 124 may be mounted to enclosure 118within recessed region 130 using a ring of adhesive film (double-sidedtape) 132 or other suitable attachment mechanism.

A cross-sectional side view of an enclosure such as enclosure 118 in thevicinity of vent opening 128 is shown in FIG. 8. Narrow vent dimension Wmay be, for example, 0.2 mm. The vent length (perpendicular to dimensionW) may be 10 mm (as an example). Speaker enclosure housing wall 210 mayhave a hole such as hole 212. Hole 212 may form an opening for speakerport 22 (FIG. 7). Speaker 214 may be mounted within enclosure 118 sothat one side of speaker diaphragm 216 is exposed to the exterior ofspeaker enclosure 118 and device 10 (e.g., exterior location 218) andthe other side of speaker diaphragm 216 is exposed to the interior ofspeaker diaphragm 216 (e.g., interior location 220).

In the example of FIGS. 7 and 8, opening 128 is formed from a vent slitin enclosure 118 that is covered by a separate air-permeable structure(mesh 134). In this type of arrangement, the opening between theinterior of enclosure 118 and the exterior of enclosure 118 is formedboth by the outline of the vent slit and by the holes in mesh 134. Ifdesired, opening 128 may be formed exclusively from holes that areformed as an integral part of enclosure 118. This type of arrangement isshown in FIG. 9.

As shown in FIG. 9, enclosure 118 may have holes 136 that are formeddirectly though the walls of enclosure 118. There may be any suitablenumbers of holes 136 (e.g., tens of holes or more). Each hole may have across-section that is relatively small in area (e.g., 0.1 mm² or less asan example). An opening formed from holes such as these may sometimes bereferred to as a microperf opening. Holes 136 may be formed bymechanical drilling, by molding, by laser drilling, or using any othersuitable technique.

As shown in FIG. 10, vent opening 128 may be formed from a separatestructure 140 into which a number of discrete holes 138 have beenformed. Structure 140 may, for example, be a metal plate or a plasticstructure. Holes 138 may be relatively small in area (e.g., 0.1 mm² orless as an example) and may be formed by mechanical drilling, molding,laser drilling, etc. Structure 140 may be attached to the housing wallsof enclosure 118 using adhesive 142 or other suitable attachmentmechanisms.

If desired, a structure such as structure 140 may be connected toenclosure 118 using a plastic overmolding process. This type ofarrangement is shown in the cross-sectional view of FIG. 11. As withholes 138 of FIG. 10, holes 138 of FIG. 11 may be relatively small inarea (e.g., 0.1 mm² or less as an example) and may be formed bymechanical drilling, molding, laser drilling, etc. Structure 140 may beformed from metal, plastic, or other suitable material.

An exploded perspective view of speaker enclosure 118 and associatedcomponents in device 10 is shown in FIG. 12. As shown in FIG. 12,components such as antenna flex 147 and dock connector 20 (andassociated flex paths and circuit components) may be mounted on speakerenclosure 118. In this capacity, speaker enclosure 118 may serve as aunifying structure for multiple parts of device 10. This can ease thetask of assembling device 10.

Speaker box 118 may have portions defining an opening for speaker port22. A mesh cover 148 (e.g., metal mesh) may be placed over opening 22.If desired, a layer of acoustic mesh such as mesh 86 of FIG. 4 may beplaced behind mesh 148. Mesh 146 (e.g., a metal mesh) may be used tocover microphone 76. If desired, a layer of acoustic mesh such as mesh86 may also be placed behind mesh 146.

Microphone 76 may have an associated elastomeric structure 152(sometimes referred to as a “boot”). Structure 152 may be formed of anysuitable material. With one suitable arrangement, structure 152 isformed from a soft material such as silicone, which allows structure 152to form good environmental seals with portions of device 10.

During assembly, microphone boot 152 may be mounted in a mating hole 144within speaker enclosure 118. Hole 144 may have features that engageboot 152 and that help to form seals between boot 152 and device 10.These seals and associated seals formed between boot 152 and the wallsof housing 12 may help prevent intrusion of moisture or particles intothe interior of device 10. Region 158 of boot 152 may have one or moresealing features such as raised ribs. These sealing features may help toenhance the quality of the seal formed between boot 152 and plastichousing 12. One or more holes such as hole 156 may be used to allowsound to enter microphone 76.

As shown in FIG. 13, microphone boot 152 may have sealing features suchas raised ribs 160. There are two ribs 160 in the example of FIG. 13. Ingeneral, boot 152 may have any suitable number of ribs. Moreover, thesesealing features may have any suitable shape. It may be desirable (asshown in FIG. 13) to form ribs 160 completely around boot 152 tocompletely seal the inner surface of port 24.

At its front end 186 (FIG. 14), microphone boot 152 may formenvironmental seals with housing 12. At rear end 192 (FIG. 15),microphone boot 152 may form environmental seals with microphone unit190.

As shown in FIG. 14, housing 12 may have an opening 194 that formsmicrophone port 24. Metal mesh 146 may be mounted to an inner surface ofhousing 12 using a ring of adhesive film 168 or other suitableattachment arrangement. As described in connection with FIG. 4, a layerof acoustic mesh such as acoustic mesh 147 may be mounted behind metalmesh 146. Boot 152 may bear against acoustic mesh 147 in regions 170,thereby forming a face seal within housing 12 that helps to preventintrusion of foreign matter into the interior of housing 12. A radialseal is formed by raised ribs 160 and adjacent portions of boot 152 inregion 172.

As shown in FIG. 14, bezel 14 may be connected to housing 12. A gasket162 may help to separate cover glass 62 from bezel 14. Cover glass 62may be mounted on frame 166 using adhesive 164.

At the rear of microphone boot 152, boot 152 forms seals with microphoneunit 190 as shown in FIG. 15. Microphone unit 190 may include microphoneelement 188, terminal support structure 184, stiffener 180 (e.g.,polyimide), and flex printed circuit 182. Terminals 178 may protrudethrough support 184, stiffener 180, and flex circuit 182. Flex printedcircuit 182 may include conductive traces for routing microphone signalsto and from the terminals of microphone unit 190.

To prevent intrusion of foreign matter, microphone unit 190 may formenvironmental seals with boot 152. In particular, the front face, rearface, and the surfaces between the front and rear faces of microphoneelement 188 may form front face seal 172, radial seal 174, and rear faceseal 176, respectively. These seals between microphone unit 190 and boot152 ensure that end 192 is well sealed.

To ensure that the front radial seal formed using sealing features suchas raised ribs 160 is satisfactory, housing 12 may have recesses thatmate with the sealing features of boot 152. As shown in FIG. 16, whenboot 152 has semicircular raised ribs, housing 12 may be provided withmating semicircular recesses 196 (as an example). FIG. 17 shows anillustrative exit hole 156 through boot 152 and shows how ribs 160 maysurround boot 152.

If desired, other shapes may be used for the radial seal sealingfeatures of boot 152. FIG. 18 shows an arrangement in which boot 152 hassemicircular recesses 200 and housing 12 has mating semicircularprotrusions 198.

FIG. 19 shows an arrangement in which boot 152 has raised triangularfeatures 204 and housing 12 has triangular recesses. In FIG. 20, boot208 has a protrusion with a square profile 208 that mates with asquare-profile recess 206 in housing 12. If desired, arrangements suchas the arrangements of FIGS. 19 and 20 may be inverted (e.g., withtriangular recesses in boot 152 or square recesses in boot 152). Thearrangements of FIGS. 16-20 may be used in any combination and anysuitable number of radial seal sealing features of this type may be usedto help form environmental seals for boot 152. Sealing features such asthese may also be used in rear portion 192 (e.g., to form seals betweenmicrophone unit 190 and boot 152).

The foregoing is merely illustrative of the principles of this inventionand various modifications can be made by those skilled in the artwithout departing from the scope and spirit of the invention.

1. A portable electronic device acoustic structure, comprising: asubstantially sealed speaker enclosure having an interior and anexterior; and a speaker within the speaker enclosure, wherein thespeaker has a diaphragm with one side exposed to the exterior of thesealed speaker enclosure and another side exposed to the interior of thesealed speaker enclosure so that acoustically the sealed speakerenclosure serves as a closed speaker box for the speaker and wherein thesubstantially sealed speaker enclosure has a vent between the interiorand exterior of the speaker enclosure that allows air pressure toequalize between the exterior and interior.
 2. The portable electronicdevice acoustic structure defined in claim 1 wherein the speakerenclosure is formed from two halves and wherein the vent is formed at aseam between the two plastic halves.
 3. The portable electronic deviceacoustic structure defined in claim 1 wherein the speaker enclosurecomprises a housing wall in which the vent forms a slit.
 4. The portableelectronic device acoustic structure defined in claim 1 furthercomprising speaker fabric mounted over the vent.
 5. The portableelectronic device acoustic structure defined in claim 1 wherein thespeaker enclosure comprises a housing wall and wherein the vent isformed from multiple holes passing through the housing wall.
 6. Theportable electronic device acoustic structure defined in claim 1 whereinthe speaker enclosure has a metal portion mounted to a plastic housingwall and wherein the vent is formed from at least one opening in themetal portion.
 7. The portable electronic device acoustic structuredefined in claim 1 wherein the speaker enclosure is formed from twohalves, wherein the vent is formed at a seam between the two plastichalves, and wherein the speaker enclosure comprises a housing wallstructure in which the vent forms a slit.
 8. The portable electronicdevice acoustic structure defined in claim 7 further comprising anonmetallic fabric mounted over the vent.
 9. The portable electronicdevice acoustic structure defined in claim 8 further comprising amicrophone boot mounted to the speaker enclosure.